Reclining chair mechanism



Filed April 1 8; 196e A umm mmm Feb. l17, 1970 N. w. M|zELLE REGLININGCHAIR MEcHANIsM v :sp1-11.18. v196:3

6 sheets-sheet 2 Filed Feb. 17, 1970 N. w. MIZELLE REGLINING CHAIRMECHANISM s sheets-sheet a Filed April 1s, 196s Feb. 17, 1970 N. w.MIZELLEl 3,495,870

v RECLINING CHAIR MECHANISM l 'Filed April 18, 196s e sheets-sheet 4 17o175 '|90 19 f x f f 2 FlEl- El N. w.V MlzELLE r 3,495,870A

RECLINING CHAIR ECHANISI v y Feb.' 17,- 19,70

s sheen-sunt 5 Filed April 1s, l196s United States Patent O 3,495,870RECLINING CHAIR MECHANISM Ned W. Mzelle, High Point, N.C., assignor toGeneral Steel Products, Inc., a corporation of North Carolina Filed Apr.18, 1968, Ser. No. 722,423 Int. Cl. A47c 1/034 U.S. Cl. 297-84 14 ClaimsABSTRACT OF THE DISCLOSURE A three position reclining chair mechanism inwhich the seat and back move as a unit from upright position to anintermediate position while a retracted leg rest is extended, and inwhich a parallel linkage system elevates the rear of the seat andreclines the back during further movement to a reclining position whilethe extended leg rest remains substantially fixed relative to the seat.

Background of the invention Three position reclining chair mechanismsare those in which the seat and back are movable between an uprightposition, an intermediate position which is still sufciently upright forreading or television viewing, and a reclining position in which theoccupant of the chair is more or less recumbent. Desirably such chairsare provided with a retractable and extendable leg rest which issubstantially completely extended during a lirst movement of the seatand back from upright position to intermediate position, and whichremains in a substantially xed position.

Prior art three position reclining chairs have had a number ofundesirable characteristics, among which are the fact that there is adefinite stopping of movement between the lirst movement and the furthermovement, with relative difficulty of initiating the further movement;that once further movement is started the chair cannot be readilybalanced in a position between the intermediate and full recliningposition; that the leg rest is unduly elevated between the intermediateposition and full reclining position; that the front of the seat movesupwardly an excessive distance during movement from upright position tofull reclining position; and that the angle between the seat and theback cannot open enough for the occupant to assume a substantiallyrecumbent position.

The structure of the present invention eliminates all the aboveenumerated disadvantages of the prior art reclining chair mechanisms,and in addition is readily adaptable to use in combined rocking andreclining chair mechanisms, and affords extremely versatile stylingpossibilities for chair manufacturers using the mechanism.

Summary of the invention In accordance with the present invention, areclining chair mechanism is of the common type in which two identicalsets of hardware are mounted on opposite sides of a chair base, and thechair seat and back are secured to the two sets of hardware. Leg restbrackets are adapted to receive upholstered leg rest members. Each setof hardware includes a base plate on which the entire mechanism ispivotally supported.

The present mechanism has a seat member, and a back bracket is pivotedat the rear end of the seat member and extended rearwardly therefrom. Afront seat support arm pivotally mounts the seat member relative to thebase, and a back support arm pivotally mounts the 3,495,870 PatentedFeb. 17, 1970 ICC pivoted to the forward of the two parallel links,which has an intermediate pivotal connection to the rearward of the twoparallel links, and which has its upper end pivotally connected to therear of the seat member. A retractable and extendable leg rest mechanismis pivotally mounted near the front of the seat, and one part of thepivotal mounting for the leg rest mechanism is an extension of the frontseat support arm, so that as the seat swings rearwardly on the frontsupport arm from upright position to intermediate position the leg restis fully extended.

During the first -movement of the chair mechanism from upright positionto intermediate position the rear seat support link swings rearwardlyand downwardly about its intermediate pivot on the rear parallel link,while at the same time the front seat support arm and the back supportarm move in parallel with the rear seat support link so that the seatand back swing rearwardly as a unit. During this rst movement the frontparallel link of the rear seat support linkage idles upwardly andforwardly with the lower portion of the rear seat support link to a deadcenter position.

With the chair in intermediate position, all the occupant of the chairneed do to move it to full reclining position is to shift his weightslightly against the back of the chair which swings the front parallellink above its dead center position and permits the two parallel linksto swing upwardly and elevate the rear seat support link and the rear ofthe seat with respect to the base. During this movement the backbracket, because it is directly connected to the base by the backsupport arm, is caused to swing downwardly about its pivotal connectionwith the rear of the seat member so that in reclining position the backof the chair occupies a very wide angle with reference to the seat.During such further movement the upward pivoting of the seat member isabout its pivotal connection with the front seat support arm. Thus,there is little relative movement between the seat and the leg rest, andno movement of the leg rest during such further movement of the chair.

In a preferred embodiment of the invention the seat member is notmounted directly upon the base at the front, but instead there is a longmounting link which is pivoted toward the rear of the base and extendsforwardly with the front seat support arm pivoted at its forward end.Forward of its pivotal connection with the base the long mounting arm islinked to the base through a short forward link and one arm of a bellcrank which has its other arm connected by a long coordinating link withthe back parallel link of the rear seat support linkage. Accordingly, inthis form of the invention the front of the seat moves up about onethird as far as does the back of the seat during the further movementfrom intermediate position to reclining position.

The reclining chair mechanism of the present invention lends itself toincorporation into a variety of reclining chair structures, either lowleg or high leg, and by merely changing the shape of the seat member thesame mechanism is adapted for use either with an inner spring seatcushion or with horizontally sinusoidal seat springs.

In a simplified and somewhat less complex and costly modification of themechanism, the long support link and associated bell crank, etc. areeliminated, and the front seat support arm is pivoted directly on thebase. In this simplied form, of course, the front of the seat is notelevated with the rear of the seat during 'further movement fromintermediate position to full reclining position.

The principal object of the present invention, therefore, is to providea reclining chair mechanism which may be used in a wide variety ofreclining chair constructions of various styles and types.

A further object of the invention is to provide a reclining chairmechanism of the three position type in which the chair may be movedfrom upright position to intermediate position and on to fully recliningposition with ease, and with the ability to balance the occupant in anyposition between intermediate position and fully reclined position byslight body movement.

Yet another obiect of the invention is to provide a three positionreclining chair mechanism in which relative movement between the seatand the leg rest during travel of the chair from intermediate positionto reclining position is very slight.

Yet another object of the invention is to provide a reclining chairmechanism in which the rear of the seat is elevated as the back isreclined during movement from intermediate position to recliningposition, so as to afford a maximum angle of inclination between theseat and the back when the chair is fully reclined and there-by permitthe occupant to assume a nearly recumbent position.

Description of the drawings FIG. 1 is a longitudinal sectional view ofthe high leg reclining chair embodying a iirst form of the recliningchair mechanism of the invention with the mechanism and the chair partsin upright position;

FIG. 2 is a fragmentary view similar to FIG. 1 illustrating the firstembodiment of the mechanism in intermediate, or television viewingposition;

FIG. 3 is a view like FIG. 2 illustrating the mechanism in recliningposition;

FIG. 4 is a sectional View taken substantially as illustrated along theline 4-4 of FIG. 2;

FIG. 5 illustrates the mechanism of a second .form of the invention withthe mechanism in upright position;

FIG. 6 illustrates the second form of the invention in intermediateposition;

FIG. 7 illustrates the second form of the invention in recliningposition;

FIG. 8 is a sectional view taken substantially as illustrated along theline 8-8 of FIG. 6;

FIG. 9 is a side elevational view of the mechanism of a third form ofthe invention illustrated in upright position;

FIG. 10 is a view showing the third form of the mechanism inintermediate position; and

FIG. 11 is a view illustrating the mechanism of the third form of theinvention in reclining position.

Detailed description of the invention Referring to the drawings ingreater detail, and referring first to FIGS. 1 to 4, a reclining chairhas a rectangular wooden base, indicated generally at 20, which includesside rails 21, back bars 22 and 23, and a forward cross member 24,together with front legs 25 and rear legs 26. Arm frames 27 surmount theside rails 21 and are adapted to be upholstered in any desired manner.

The reclining chair mechanism of the first form of the present inventionincludes a base plate 30 which is screwed to one of the side rails 21 ofthe chair frame, and the entire mechanism is mounted upon the base plate30 so that a furniture manufacturer need only mount a pair of such baseplates on the opposite side rails 21 of a chair frame, mount anupholstered seat (not shown) on seat members 31 of the two mechanisms,mount a back frame suitable for upholstering on back brackets 32 of thetwo mechanisms, and mount leg rests boards 29a and 29b, suitable forupholstering, upon leg rest brackets 33a and 33b,` respectively of thetwo mechanisms. The leg rest brackets are pivotally connected at 33C.

In the first form of the invention the seat member 31 is supported upona front support linkage, indicated generally at 34, and upon a rearsupport linkage, indicated generally at 35. The seat member 31 has acentral portion 36 which is adapted to receive a drop-in coil springbase, and at the front of the central portion 36 the seat member has anupwardly and forwardly extending p0rtion 37 which terminates in amounting arm portion 38, while at the rear of the central portion 36there is an upwardly extending arm portion 39 which forms the back ofthe seat member. The back bracket 32 is pivoted at 40 on the upper endof the seat arm 39.

The front seat support linkage 34 includes a long support arm 41 whichis pivotally mounted at 42 toward the rear of the base plate 30, and afront seat support arm 43 is pivoted at 44 on the front of the longsupport arm 41 and at 45 has a pivotal connection with the mounting armportion 38 of the seat member 31. The front seat support linkage 34 alsoincludes a bell crank 46 which is pivoted at `47 on the base and has afirst arm 48 and a second arm 49. A short link 50 is pivotally mountedat 51 on the first arm 48 of the bell crank and is pivotally connectedat 52 to the long support arm 41. A long coordinating link 53 is pivotedat 54 to the second arm 49 of the bell crank, and at 55 to a rearparallel link 56 of the rear seat support linkage means 35.

As best seen in FIG. 3, the rear seat support linkage means 35 includesthe rear parallel link 56 which is pivotally mounted on the base 30 at57, a front parallel link 58 which has a longitudinal slot 59 by meansof which it makes a lost motion connection with a rivet 60 on which itis pivotally supported on the base 30, and a rear support link 61 whichhas a lower pivotal connection 62 with the front parallel link 58, anintermediate pivotal connection 63 with the rear parallel links 56, andan upper pivotal connection 64 with the rear arm portion 39 of the seatmember 31. Thus, the rear support link 61 supports the rear of the seatmember 31 and is operatively mounted upon the rear parallel link 56 andthe front parallel link 58. Movement of the rear parallel link 56 islimited by a slot 56a| which is impaled by a stud. The back bracket 32is supported by a back bracket support arm 65 to which it is pivotallyconnected at 66, and the support arm 65 is pivotally mounted upon thebase 30 on the same pivot 57 which carries the rear parallel link 56.

The leg rest brackets 33a and 33b are mounted on a retractable andextensible leg rest linkage which is best seen in FIGS. 2 and 3. Itincludes a hanger link 67 which is pivoted at 68 on the forward portionof the long support arm, and an arm 69 which is an extension of thefront seat support arm 43 below the pivot 44. A link 70 is pivoted onthe link 67 at 71, on the arm 69 at 72, and on the bracket 33a at 73. Alink 74 is pivoted intermediate its ends at 75 on the link 70, and alink 76 connects the arm 69 to the link 74 through a pivot 77 on the armand a pivot 78 on the link 74. A bell crank 79 is pivoted at 80 on thebracket 33a and has one arm pivotally connected at 81 to the link 74. Alink 82 connects the other arm of the bell crank to the bracket 33b by apivot S3 on the bell crank and a pivot 84 on the bracket.

Thus, the links 67, 70, 74, 76 and 79, together with the arm extension69, act as a lazy tongs linkage to extend the leg rest as the front seatsupport arm 43 moves from the upright position of FIG. l to theintermediate position of FIG. 2. The bell crank 79 and the link 82cooperate with the pivotally connected leg rest brackets 33a and 33b tounfold the bracket 33b with respect to the bracket 33a during saidmovement of the leg rest linkage.

The link 67 has a flat surface 67a which cooperates with a surface 69aon the support arm extension 69 to stop the unfolding movement of theleg rest.

A comparison of FIGS. 1, 2 and 3 shows that as the reclining chairmechanism moves from the upright position of FIG. 1 to the intermediateposition of FIG. 2 the front seat support arm 43, the rear support link61 and the back bracket support arm 65 swing rearwardly in parallelabout their respective pivots 44, 63 and 57 so that the front of theseat member 31 swings upwardly on a short are and then slightlydownwardly, while the rear of the seat member and the back bracket swingrearwardly and downwardly as a unit without relative motion betweenthem. At the same time, the leg rest operating arm 69, the extension ofthe front seat support arm 43, extends the leg rest linkage and pivotsthe leg rest bracket 33b into alignment with the leg rest bracket 33a.

During the further movement from the intermediate position of FIG. 2. tothe reclining position of FIG. 3, the front seat support linkage and therear seat support linkage cooperate to elevate the entire Seat member 31a short distance at the front and a considerably greater distance at therear while the 4back bracket 32 pivots downwardly with respect to theseat member about the pivot 40. The elevating of the seat member 31 isproduced by rotation of the bell crank 46 and of the two parallel links56 and 58 of the rear seat support linkage, coordinated through thecoordinating link 53. Rotation of the bell crank 46 about its pivot 47acts through the short link 50 to pivot the long support arm 41 aboutits pivotal connection 42 to the base 30, and thus elevate the front ofthe seat. At the same time, the rear parallel link 56 and the frontparallel link 58 pivot about their respective pivotal connections 57 and60 with the frame to elevate the supporting link 61 and thus elevate therear of the seat member. Since the back bracket 32 is linked to the base30 by the back support arm 65, it is forced to pivot downwardly aboutthe pivot 40 as the rear of the seat is elevated.

It will be observed that in the upright position of FIG. l and theintermediate position of FIG. 2 the pivotal connection 63 between therear support link 61 and they rear parallel link 56 is coaxial with thepivotal connection 60 between the front parallel link 58 and the base30, so that during the first movement of the chair, from uprightposition to intermediate position, the front parallel link idlesupwardly and forwardly about the pivot 60 with the lower portion of therear support link 61, and that in the intermediate position of FIG. 2the front parallel link has reached a dead center position in which thepivot 62 which connects it with the rear support link 61 is aligned withthe pivot 57 of the rear parallel link and the pivotal connection 63 ofthe support link 61 and the rear parallel link. Accordingly, the frontparallel link 58 serves, during the rst movement of the seat and back,to lock the parallel linkage against rotation, whereas when the link 58reaches the dead center position the parallel links are free to move inunison. The slotted connection 59-60 for the front parallel link 58provides a lost motion connection between that link and the base 30without which the link could not idle upwardly and forwardly about thepivot 60 from the position of FIG. l to the position of FIG. 2.

Referring now to the second form of the invention illustrated in FIGS. 5to 8, the mechanism is similar to that of the first form of theinvention except that the front support linkage means is eliminated, andthe leg rest is of the one piece type `which has an operating linkagethat extends a substantial distance below the chair seat and thus is notadaptable to a high leg chair style as is the rst form of the invention.However, it is apparent to those skilled in the art that either type ofleg rest may be used with the rst form of the invention or with thesecond form of the invention.

The second mechanism includes a base plate 130', a seat member 131 whichis identical with the seat member 31, and a back bracket 132 which ispivoted to the rear of the seat member 131 at 140. A front seat supportarm 143 is pivoted on the base 130 at 144, and is pivotally connected tothe front of the seat member 131 at 145.

A rear seat support linkage 135 is identical to the rear support linkage35 of the first form of the invention, and includes a rear parallel link156y pivoted on the base 130 and 1-57, and a front parallel link 158having a longitudinal slot 159 by means of which it makes a lost motionconnection with a pin 160 on the base 130. A rear support link 161 ispivotally connected at its lower end to a pivot 162 on the frontparallel link 158, has an intermediate pivotal connection 163 with therear parallel link 156, and has an upper pivotal connection 164 with therear of the seat member 131. A back bracket support arm 165 is pivotedat 166 to the -back bracket 132 and is connected to the base 130 at thepivot 157 of the rear parallel link 156. A downward extension 165:1 ofthe back bracket support arm 165 is provided with an aperture, and anintegral bracket portion 158a on the front parallel link 158 is providedwith a slot so that a tension spring may be interposed between theextension 165a and the bracket portion 158a to urge the mechanism towardthe upright position of FIG. 5.

The extensible and retractable leg rest mechanism includes a leg restbracket 133 which is moved by a linkage that includes a link 167 pivotedat 168 on the base 130, an extension arm 169 of the front seat supportarm 143, a long link 170 which is pivoted at 171 to the link 167, at 172to the arm 169, and at 173 to the leg rest bracket 133. A link ispivoted at 191 to the arm 169 and at 192 to the leg rest bracket 133.Thus, the links 167, 170, 190 and the arm 169 function as a lazy tongslinkage so that, when the chair mechanism is moved from the uprightposition of FIG. 5 to the intermediate position of FIG. 6 the rearwardswinging movement of the front seat support arm 143 and thecorresponding forward swinging movemnt of the leg rest arm 169 extendthe leg rest as seen in FIG. 6.

In operation the second form of the mechanism functions much as does thefirst form, except that since there is no front support linkage thefront of the seat member 131 is not elevated during movement from theintermediate position of FIG. 6 to the reclining position of FIG. 7.Otherwise the operation is the same,V with the seat member swingingrearwardly and downwardly during the first movement about the front seatsupport arm 143, the back bracket support arm 165 and the rear supportlink 161, said arms and said link moving in parallel so that there is norelative motion beteen the back bracket 132 and the seat member 131.During the second movement from the position of FIG. 6 to the positionof FIG. 7 the parallel links 156 and 158 of the rear seat supportlinkage swing in parallel about their respective pivots 157 and 160 soas to elevate the rear support link 161 and thus swing the seat member131 upwardly about its pivotal connection 145 with the front seatsupport arm 143. During this movement the link 165 causes the backsupport bracket 132 to swing downwardly about the pivot '.140 on theback of the seat member 131.

As in the first form of the invention, the front parallel link 158 idlesupwardly and forwardly about the pivot 160 during the rst movement, andunitl it reaches the dead center position the parallel links 156 and 158are locked against parallel movement. The lost motion connection betweenthe link 158 and the base 130 permits the idling movement of the link158 during the travel of the mechanism between the upright position ofFIG. 5 and the intermediated position of FIG. 6.

Referring now to FIGS. 9, l0 and 11, which illustrate the third form ofthe invention, the mechanism is seen to be exactly like that of thefirst form except that the unit has a seat member, indicated generallyat 231, the structure of which is different from that of the seat-member 31. As indicated `in the detailed description of the first form,the drop center portion 36 of the seat member 31 adapts it to support adrop-in coil spring base. In contrast, the seat member 231 extendsstraight from front to rear, and thus is particularly adapted to receivea seat structure consisting of horizontally oriented serpentine springmembers of the type commonly used in upholstered furniture.

The dimensions of the seat member 231 from its front pivot 245 to itsrear upright arm 239 are identical with those of the seat member 31, sothat a manufacturer of reclining chair mechanisms may supply a customereither with a mechanism to receive a drop-in coii spring base or with amehanism to receive a serpentine spring seat cushion merely by usingeither the seat member 31 or the seat member 231. All other parts in thetwo units are identical, and thus no further detailed description of thethird form of the invention is given herein although the drawings arenumbered with reference numerals corresponding to those of the rst formof the invention but 200 numbers higher in each case.

As is well known in the art, and as previously suggested herein, varioussubstitutions of parts may be made as, for example, using a .leg restand leg rest linkage like that of the second orrn of the invention onthe structure of the iirst or third lform of the invention, or by usingthe leg rest and leg rest operating mechanism of the iirst and thirdforms of the invention, with the second form of the invention.Similarly, the seat member 231 of the rst form of the invention may besubstituted for the seat member 131 in the second form of the inventionif a customer desires the combination of the lower priced linkage withthe seat member designed to receive the lower cost type of upholsteredseat.

In view of the fact that each of the last above mentioned modificationswould be obvious to one skilled in the art in View of the structureillustrated and described for the rst three forms, no more detail ofsuch modications is given herein.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations are to be understoodtherefrom, as modifications will be obvious to those skilled in the art.

I claim:

1. In a three position reclining chair mechanism, combination: a base; aseat member; a back bracket member pivoted on the rear of the seatmember and extending rearwardly therefrom; a front seat support armpivotally mounting the front of the seat member relative to the base; aback support arm pivotally mounting the back bracket on the base behindthe seat member, said support arms swinging rearwardly substantially inparallel as the seat member and back bracket perform a rst movement froman upright position to an intermediate position so that said member andsaid bracket move between said positions substantially without relaitvemovement; and linkage means supporting the rear of the seat member onthe base, said linkage means including front and rear parallel linkspivoted on the base and a support link pivoted on said links andpivotally connected at its upper end to the rear of the seat member, theupper end of said support link swinging rearwardly and downwardly aboutits connection to the rear parallel link during rst movement of the seatmember and back bracket, and said parallel links cooperating to elevatesaid support link and the rear of the seat member during a furthermovement from intermediate position to reclining position, said supportlink and said back support arm cooperating to pivot the back bracketdownwardly about its pivotal connection to the seat member during saidfurther movement.

2. The mechanism of claim 1 in which the front parallel link has a lostmotion connection, the support link is mounted on the front parallellink at its lower end and has an intermediate pivotal connection withthe rear parallel link, and in which the front parallel link pivots idlyforwardly and upwardly with the lower part oi the support link to a deadcenter position during the rst movement.

3. The mechanism of claim 1 which includes an extensible and retractableleg rest pivotally mounted adjacent the front of the base, and in whichthe front seat support arm has an extension which provides part of thepivotal mounting for the leg rest so that the irst movement of the seatmember extends the leg rest.

4. The mechanism of claim i in which the seat member pivots about thefront seat support arm during said further movement.

5. The mechanism of claim 1 where includes a long support arm pivotallymounted toward the rear of the base and having the front seat supportarm pivotally mounted at its front end, a bell crank pivotally mountedon the base below sai-d long suport arm, a short link connecting ai'lrst arm of the bell crank to the long support arm, and a longcoordinating link connecting the second arm of the bell crank to therear parallel link.

5. The mechanism of claim S which includes an extensible and retractableleg rest which is pivotally mounted on the front portion of the longsupport arm, and in which the front seat support arm has an extensionwhich provides part of the pivotal mounting for the leg rest so that therst movement of the seat member extends the leg rest.

7. The mechanism of claim 1 in which the seat member is substantiallystraight from front to rear, and has an upwardly extending portie-n atthe rear in which the pivots for the back bracket and the support linkare mounted.

Vv8. The mechanism of claim 1 in which the seat member has a centralportion adapted to receive a drop-in spring base, the front portion ofthe seat member extends forwardly and upwardiy from said centralportion, and there is an upwardly extending portion at the rear of saidcentral portion in which the pivots for the back bracket and the supportlink are mounted.

9. In a three position reclining chair mechanism, in combination a base;

a seat member;

a back bracket pivoted on the rear of the seat member and extendingrearwardly therefrom;

front linkage means mounting the front of the seat member on the base,said front linkage means including a long support arm pivoted on thebase, a plurality of links adapted toraise and lower the front of saidsupport arm, and a front seat support arm pivotally mounting the frontof the seat member on the long support arm;

rear linkage means mounting the rear of the seat member on the 1oase,said rear linkage means including a plurality of links pivoted on thebase and a support link connecting the rear of the seat member with saidplurality of links;

a back support arm pivotally mounting the back bracket on the basebehind the seat member;

a coordinating link connecting the front linkage means and the rearlinkage means; said front and rear linkage means and said back supportarm cooperating to support the seat and back bracket for a rst unitaryrearward swinging movement from an upright position to an intermediateposition, and said front and rear linkage means cooperating duringfurther movement to elevate the front and rear of the seat member whilesaid back support arm causes the back bracket to tilt downwardlyrelative to the rear of the seat member;

and extensible and retractable leg rest means swingingly suspended fromthe front of the front linkage means and operatively connected with thefront seat support arm so that the leg rest is substantially fullyextended during irst movement.

10. The mechanism of claim 9 in which the plurality of links in thefront linkage means comprises a bell crank pivoted on the base and ashort link pivoted on one arm of the bell crank and on the long supportarm, and in which the coordinating link is pivotally connected to theother arm of the bell crank.

11. The mechanism or" claim 9 in which the plurality of links in therear linkage means comprises front and rear parallel links pivoted onthe base, and in which the rear support link is pivoted at its lower endon the front parallel link, is pivoted intermediate its ends on the rearparallel link, and is pivoted at its upper end on the seat member.

12. The mechanism of claim 11 in which the coordinating link ispivotally connected to the rear parallel link.

13. The mechanism of claim 12 in which the plurality of links in thefront linkage means comprises a bell crank pivoted on the base and ashort link piv'oted on one arm of the bell crank and on the long supportarm, and in which the coordinating link is pivotally connected to theother arm of the bell crank.

14. The mechanism of claim 9 in which the relationship between the frontlinkage means, the rear linkage means and the coordinating link is suchthat during said further movement the rear of the seat member elevatesmore than twice as far as does the front of the seat member.

References Cited UNITED STATES PATENTS JAMES T. McCALL, Primary Examiner

